您当前的位置: android 如何使图片变灰
------解决方案--------------------
是把彩色图像转换为灰度图是不是？
我帮你写了一段代码，测试通过。方法的两个参数分别是源文件，目标文件在Android内的路径位置。
要注意的是，存取SD卡的话，必须在AndroidManifest.xml文件中加上一行
<uses-permission android:name = "android.permission.WRITE_EXTERNAL_STORAGE" />
否则创建文件会失败。
- Java code
package com.example;
import java.io.*;
import android.graphics.*;
import android.graphics.Bitmap.CompressFormat;
public class ReadImage
{
public static void toGrayImage(String source, String dest)
{
try
{
Bitmap bitmap = BitmapFactory.decodeFile(source);
int width = bitmap.getWidth();
int height = bitmap.getHeight();
Bitmap grayImg = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
//
Canvas canvas = new Canvas(grayImg);
Paint paint = new Paint();
ColorMatrix colorMatrix = new ColorMatrix();
colorMatrix.setSaturation(0);
ColorMatrixColorFilter colorMatrixFilter = new ColorMatrixColorFilter(
colorMatrix);
paint.setColorFilter(colorMatrixFilter);
canvas.drawBitmap(bitmap, 0, 0, paint);
// canvas.
File file = new File(dest);
boolean success = file.createNewFile();
FileOutputStream stream = new FileOutputStream(file);
grayImg.compress(CompressFormat.JPEG, 100, stream);
stream.flush();
stream.close();
bitmap.recycle();
grayImg.recycle();
}
catch (Exception e)
{
@SuppressWarnings("unused")
String msg = e.getMessage();
}
}
}